Cream the butter and sugar until pale and fluffy. Add the vanilla and mix, then the flour and mix.
Form a dough with your hands and roll out to about 5mm. Get an Olaf/snowman cutter and cut the dough. Lay on a lightly greased baking tray.
Bake in the preheated oven for 25 minutes or until golden brown. Remove from the oven and transfer to a cooling rack to cool.
Meanwhile put the icing sugar in a bowl. Add the water and mix well. If too thick add a bit more water. If too runny add more icing sugar. Spread on biscuits and leave to set. When set, make buttons, nose and eyes on the snowman with the writing icing.
Add different flavours. You could purchase your Olaf cutter from a Olaf biscuit making set available from most food stores.